This study examined the impact of applying straw as a substitute for chemical fertilizers on the characteristics of greenhouse gas emissions in farmland ecosystems within semiarid regions. This long-term and continuous field trial began in 2016 and established two control groups: a fertilization control (CK) and four treatment groups (25 %, 50 %, 75 %, and 100 % straw nitrogen in place of the inorganic nitrogen treatment, labelled S25, S50, S75, and S100, respectively). The study integrated the net ecosystem carbon budget, net global warming potential, greenhouse gas emission intensity and carbon emission efficiency and explored their relationships with soil structural properties such as capillary porosity and bulk density. The results showed that S75 had the highest cumulative methane absorption in 2022 and 2023, while S100 had the lowest cumulative nitrous oxide emissions, and the net global warming potential was significantly reduced. In the elongation of 2022, the nitrous oxide emission flux of S100 decreased significantly by 58.1 %-74.7 % compared with other treatments, respectively. S100 reduced the cumulative carbon dioxide emissions by 13.9 %-72.2 % in 2 years, respectively. The nitrous oxide emission factor under S100 was negative in 2022. The highest net ecosystem carbon budget (26.6 C ha(-1)) and carbon emission efficiency (3.53 kg kg(-1)) were observed in 2022 under S100, which were significantly higher than those under other treatments. In 2023, only S100 showed negative greenhouse gas emission intensity. In conclusion, S100 was demonstrated to enhance the soil carbon sink function while maintaining the yield of maize (Zea mays) that was statistically comparable to the high-yield treatments (S50/S75).